This allows me to access all my frequently used saved functions and variables. I essentially only use Sage through the web interface, and I would like to know if it is possible to make this code run as a "prefix" so that I no longer have to type this include in every worksheet.

@Mike Witt: Yes, init.sage should work in both, but it wasn't clear whether process91 is using it on a remote server or on his/her own computer. "Only" modified "your own computer", not the whole following phrase :)